Question: Solve for $z$, $- \dfrac{z - 6}{2z + 1} = 10$
Explanation: Multiply both sides of the equation by $2z + 1$ $ -(z - 6) = 10(2z + 1) $ $-z + 6 = 20z + 10$ $6 = 21z + 10$ $-4 = 21z$ $21z = -4$ $z = -\dfrac{4}{21}$